Then I guess we're pretty out of luck. 5 years in a closet, and possibly more years of use before that, the drive may have gotten damaged.
As for the resume interrupted process, it should be in the System tab, 3rd from top.
If you don't have a rescue disk, you can't attempt to restore the keyfile data, etc. I'm not entirely sure on this, but if you don't mind waiting a pretty long time, you could burn a new rescue disk, and using it, decrypt the drive from boot. It'll be slower than if you did it in a OS with AES hardware acceleration, but it may bring hope to restore the files on the drive. Don't try to restore anything from it however, it won't have the correct headers to restore from.
If the rescue disk requires you to encrypt your current OS, use a different password than the one you used on the XP one. That way, if the rescue disk tries to decrypt using the new header it should just say wrong password, rather than overwrite encrypted data with garbage. (just a precaution here, never did this myself)
If that doesn't work, then I don't know.